Issue 10 (#14)

* ISSUE-10 Fix call to execFile with a file larger than 200KB will fail

Update the execFile call to specify the maxBuffer size to be tuneable
and larger than 200KB.  By default the plugin will now look up the
current file size and allocate 2x the buffer to allow room for
whitespace and formatting expansion.

This also fixes the issue where the plugin could not format files
that were large than 200KB.

Add a new configuation option to allow a user to tune the buffer
multiplier to custom values.

Update documentation.

* ISSUE-10 Fix a comment

* Accidentally inserted tabs.  Switch to spaces.

* Capture the default maxBuffer size for execFile. Choose the maximum of
calculated new multiplier buffer size for a larger file or use the default
value for execFile to avoid any pointless buffer resizes.

README.md

@@ -20,6 +20,7 @@ Open the command palette (Ctrl-Shift-P / Cmd-Shift-P)
 
 - `astyle.astylerc`: specify path of astylerc file. ${workspaceRoot} is supported to enable using different astyle file between projects. e.g. '${workspaceRoot}/.vscode/astylerc'. (default: null, lookup astylerc in original order of astyle)
 - `astyle.cmd_options`: array of command line options for astyle. (You should avoid conflicted options) For example: `["--indent=tab", "--break-blocks"]`
+- `astyle.max_buffer_multipler`: multiplier to indicate how large an output buffer to allocate for the transformed source code file after Astyle processes it. (default: 2, assumes most formatting/whitespace expansion will result in less than a 2x increase in file size).
 - `astyle.additional_languages`: array of additional languages to use astyle as code formatter. For example: `["haxe"]`. (You don't have to enable the language in astyle config)
 
 ## FAQ

extension.js

@@ -9,11 +9,18 @@ class AstyleFormatter {
         this.statusBar = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Left);
     }
 
+    getFilesizeInBytes(filename) {
+        const stats = fs.statSync(filename)
+        const fileSizeInBytes = stats.size
+        return fileSizeInBytes
+    }
+
     // interface required by vscode.DocumentFormattingEditProvider
     provideDocumentFormattingEdits(document, options, token) {
         return new Promise((resolve, reject) => {
             let astyleBinPath = vscode.workspace.getConfiguration('astyle')['executable'] || 'astyle';
             let astyleRcPath = vscode.workspace.getConfiguration('astyle')['astylerc'];
+            const astyleMaxBufferMultiplier = vscode.workspace.getConfiguration('astyle')['max_buffer_multipler'];
             let args = vscode.workspace.getConfiguration('astyle')['cmd_options'] || [];
 
             if (astyleRcPath) {
@@ -25,16 +32,22 @@ class AstyleFormatter {
             });
 
             astyleBinPath = astyleBinPath.replace(/\${workspaceRoot}/g, vscode.workspace.rootPath);
-
-            let astyle = childProcess.execFile(astyleBinPath, args, {}, (err, stdout, stderr) => {
+
+            const defaultMaxBufferSize = 200 * 1024;
+            const maxBufferMultiplierSize = this.getFilesizeInBytes(document.fileName) * astyleMaxBufferMultiplier;
+            // Assume that the formatting/expansion of the document could double it's size
+            // Make sure the minimum size is still the default for execFile::maxBuffer
+            const maxBufferSize = Math.max(defaultMaxBufferSize, maxBufferMultiplierSize);
+
+            let astyle = childProcess.execFile(astyleBinPath, args, {maxBuffer: maxBufferSize}, (err, stdout, stderr) => {
                 if (err && err.code == 'ENOENT') {
                     vscode.window.showErrorMessage('Can\'t find astyle. (' + astyleBinPath + ')');
                     reject(null);
                     return;
                 }
 
                 if (err) {
-                    vscode.window.showErrorMessage('Failed to launch astyle. (reason: "' + stderr.split(/\r\n|\r|\n/g).join(',') + '")');
+                    vscode.window.showErrorMessage('Failed to launch astyle. (reason: "' + stderr.split(/\r\n|\r|\n/g).join(',') + ' ' + err + '")');
                     reject(null);
                     return;
                 }

package.json

@@ -46,6 +46,11 @@
                     "type": ["array"],
                     "default": [],
                     "description": "array of command line options"
+                },
+                "astyle.max_buffer_multipler": {
+                    "type": "string",
+                    "default": "2",
+                    "description": "the multiplier for the new size of a file after formatting"
                 },
                  "astyle.additional_languages": {
                     "type": ["array"],